A Newfoundland shipping firm is raising its fees, blaming higher costs because of federal measures taken to protect North Atlantic right whales after a series of deaths.

Oceanex Inc. says the four-per-cent "temporary marine protection surcharge" on service between Montreal and St. John's, N.L., follows a federal speed limit imposed last Friday in an area of the Gulf of St. Lawrence.

Ten of the endangered mammals have died in the gulf since early June — at least some after colliding with ships.

Oceanex says in a release Friday the new regulations mean its vessels must travel more quickly outside the speed-restricted zone.

It says the measure "significantly increases vessel fuel consumption" and raises labour costs in port.

In a notification to clients, Oceanex asks them to raise any concerns about the regulation with the federal government.

"As a marine transportation operator, Oceanex is cognizant of its responsibility to promote navigation safety and protection of the marine environment. As such, Oceanex is taking the necessary action to comply with the government order while still providing its customers with reliable transportation solutions," the notification says.

"Oceanex has advised the government of Canada of the significant impact of this temporary regulation and encourages you to raise any of your concerns regarding this issue with your local federal government of Canada representative."

Transport Minister Marc Garneau announced vessels of 20 metres or more will be required to slow to 10 knots — or about 19 km/h — while travelling in the western Gulf of St. Lawrence, from the Quebec north shore to just north of Prince Edward Island.

Smaller ships are being asked to voluntarily abide by the speed limit, which will remain in place until the whales have migrated from the areas of the gulf that pose the most concern.